The Slot Dipping Device has been designed to provide a convenient and safe means of manually measuring the levels and temperature and taking samples of petroleum, petrochemical, chemical and other volatile or hazardous liquids in bulk storage tanks, in pressures of up to 40" (1016 mm) WG. It is available in 6" (150 mm) size and is mounted on the roofs of tanks and can be used in place of conventional gauge hatches with the following advantages :
The device can accommodate both heavy and light dip weights and also the Temperature and Sampling Device. The Temperature and Sampling Device has been designed to provide a means of taking samples and temperature of products stored in bulk in the petroleum, petrochemical, chemical and allied industries. When used in conjunction with the Slot Dipping Device which is suitable for pressures up to 40” (1016 mm) WG, loss of vapour is greatly reduced.
All tank environmental protection equipments can be supported by our service department who can provide expert and specialist Installation and commissioning service and complete ‘on site’ equipment maintenance, repair and servicing facilities including equipment condition surveying and certification and maintenance training.
The assembly consists of an upper and lower body section with a counter balanced lever operated closing pallet in the lower section. The upper section is sized to accommodate the dip weight or sampling device when the isolating pallet in the lower section is closed. The hinged cap closing the upper section is constructed to accept the bayonet fitting of the rope or tape adaptor. When the fitting is not in use it is closed by a sealing plug. The main components - body sections, cap and closure pallet are constructed in Aluminium alloy
The lower body section is drilled to ASA 150.
Hand Gauging Tape Adaptor has a small clearance around the tape through which only a very small amount of vapour can escape and is permanently attached to the tape. When the upper section of the device is isolated from the tank by the closure pallet the plug can be removed and the tape weight inserted with the tape adaptor replacing the plug. Gauging can proceed when closure pallet has been lowered. Indicating paste is normally used when gauging spirit tanks. When gauging black oil tanks it is advisable to use the adaptor which incorporates a tape wiper. A hard Beryllium copper strip in the adaptor holds the graduated side of the tape clear of the edge of the slot. The aperture in the upper section cap is 46 mm diameter and will allow passage of all known standard tape weights and the plunger of the Portable Temperature Sensor.
Either a gauging tape or a PVC covered wire rope can be used with the corresponding adaptor. The method of sampling follows closely that for gauging except that the cap on the upper chamber is opened and the sampling device is placed in the upper section and the tape/rope connected. The tape adaptor or rope adaptor is inserted in the cap and after lowering the pallet, sampling can proceed.
The unit consists of a sample container which can be opened and closed beneath the liquid surface by the thermometer containment tube which is attached to a rope or graduated tape (see diagram). The materials are predominantly Stainless Steel and Brass.
The case is opened by raising the outer body (8) with respect to the lower end cover (11). After preliminary flushing at the required depth, the device is closed and the sample trapped by jerking the rope or tape which supports the device. Temperature variation during the time taken to raise the sample and read the thermometer is negligible, because the body (8) and disc (10) insulate the sample from its surroundings. When the temperature has been read, the sample may either be returned to the tank or decanted into a sampling bottle using the special funnel (20). A flushing time of not more than 30 seconds is required for most unheated petroleum products. Heated viscous oils may require a slightly longer immersion of up to 1 minute.